Optical Network Switching Node in Multi-Chassis Cluster, Optical Burst Synchronization Method, and Line Card Chassis

1. An optical burst synchronization method, comprising: selecting one line card chassis from multiple line card chassis connected to a same all-optical switching element, as a reference chassis, and transmitting, by an output port corresponding to a wavelength Fast tunable optical laser (FTL) in the reference chassis, an optical burst test signal by using the FTL respectively to receive ports corresponding to optical receivers (ORs) in the multiple line card chassis connected to the same all-optical switching element, wherein the optical burst test signal carries a transmission timeslot number, and acquiring, by a receive port corresponding to an optical receiver (OR) in each line card chassis connected to the same all-optical switching element, according to an optical path difference between the receive port corresponding to the OR in each line card chassis and the output port corresponding to the FTL in the reference chassis, time of receiving the optical burst test signal, and the transmission timeslot number carried in the optical burst test signal, a time-phase difference between the receive port corresponding to the OR in each line card chassis and the output port corresponding to the FTL in the reference chassis, and adjusting, according to the time-phase difference, a clock phase referenced for receiving electrical burst data on the receive port corresponding to the OR and a clock phase referenced for transmitting electrical burst data on an output port corresponding to an FTL located in the same line card chassis and corresponding to the OR.

2. The optical burst synchronization method according to claim 1 , wherein adjusting, by the receive port corresponding to the OR in each line card chassis connected to the same all-optical switching element, according to the time-phase difference, a clock phase referenced for transmitting electrical burst data on an output port corresponding to an FTL located in the same line card chassis and corresponding to the OR, comprises: adjusting, by the receive port corresponding to the OR in each line card chassis connected to the same all-optical switching element, according to the time-phase difference and an optical path difference between the receive port corresponding to the OR and the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR, the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

3. The optical burst synchronization method according to claim 2 , wherein before adjusting, by the receive port corresponding to the OR in each line card chassis connected to the same all-optical switching element, according to the time-phase difference and an optical path difference between the receive port corresponding to the OR and the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR, the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR, the method further comprises: transmitting, by the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR, an optical burst loopback signal to the receive port corresponding to the OR, wherein the optical burst loopback signal carries a transmission timeslot number, and acquiring, by the receive port corresponding to the OR, according to time of receiving the optical burst loopback signal and the transmission timeslot number carried in the optical burst loopback signal, an optical path difference between the receive port corresponding to the OR and the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

4. The optical burst synchronization method according to claim 1 further comprising: counting, by the receive port corresponding to the OR in each line card chassis connected to the same all-optical switching element, according to a preset phase detection period, clock pulses between two or more than two consecutively received optical burst test signals, and recording a count result, and adjusting, according to two consecutive count results, the clock phase referenced for receiving electrical burst data on the receive port corresponding to the OR and the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

5. The optical burst synchronization method according to claim 1 , wherein the all-optical switching element is an arrayed waveguide grating router (AWGR).

6. An optical burst synchronization method, comprising: selecting one line card chassis from multiple line card chassis connected to a same all-optical switching element, as a reference chassis; transmitting, by an output port corresponding to a wavelength-tunable optical transmission laser (FTL) in each line card chassis connected to the same all-optical switching element, an optical burst test signal by using the FTL to a receive port corresponding to an optical receiver (OR) in the reference chassis, wherein the optical burst test signal carries a transmission timeslot number, acquiring, by the receive port corresponding to the OR in the reference chassis, according to an optical path difference between the receive port corresponding to the OR in the reference chassis and the output port corresponding to the FTL in each line card chassis, time of receiving the optical burst test signal transmitted by the output port corresponding to the FTL in each line card chassis, and the transmission timeslot number carried in the optical burst test signal, a time-phase difference between the receive port corresponding to the OR in the reference chassis and the output port corresponding to the FTL in each line card chassis, and transmitting the time-phase difference between the receive port corresponding to the OR in the reference chassis and the output port corresponding to the FTL in each line card chassis to the output port corresponding to the FTL in each line card chassis; and adjusting, by the output port corresponding to the FTL in each line card chassis, according to the time-phase difference, a clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL.

7. The optical burst synchronization method according to claim 6 , further comprising: counting, by the output port corresponding to the FTL in each line card chassis connected to the same all-optical switching element, according to a preset phase detection period, a local clock between two or more than two consecutively received time-phase differences returned by the receive port corresponding to the OR in the reference chassis, and recording a count result, and adjusting, according to two consecutive count results, the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL.

8. The optical burst synchronization method according to claim 6 , wherein the all-optical switching element is an arrayed waveguide grating router (AWGR).

9. A line card chassis, comprising: a receive-end electrical switching element and a transmit-end electrical switching element, wherein the receive-end electrical switching element comprises multiple receive ports, multiple output ports, and a wavelength-tunable optical transmission laser (FTL) connected to each output port, and the transmit-end electrical switching element comprises multiple receive ports, multiple output ports, and an optical receiver (OR) connected to each receive port, wherein: the output port corresponding to each FTL is configured to transmit, when the line card chassis is selected as a reference chassis, an optical burst test signal to a receive port corresponding to an optical receiver OR in other line card chassis that are connected to a same all-optical switching element as the reference line card chassis, so that the receive port corresponding to the OR in the other line card chassis acquires, according to an optical path difference between the receive port corresponding to the OR in the other line card chassis and the output port corresponding to the FTL that transmits the reference burst test signal in the reference chassis, time of receiving the optical burst test signal, and a transmission timeslot number carried in the optical burst test signal, a time-phase difference between the receive port corresponding to the OR in the other line card chassis and the output port corresponding to the FTL in the reference chassis, and adjusts, according to the time-phase difference, a clock phase referenced for receiving electrical burst data on the receive port corresponding to the OR and a clock phase referenced for transmitting electrical burst data on an output port corresponding to an FTL located in the same line card chassis and corresponding to the OR; and the receive port corresponding to each OR is configured to receive, when one line card chassis among the other line card chassis that are connected to the same all-optical switching element as the line card chassis is selected as a reference chassis, an optical burst test signal transmitted by an output port corresponding to an FTL in the reference chassis by using the FTL, acquire, according to an optical path difference between the receive port corresponding to each OR and the output port corresponding to the FTL that transmits the optical burst test signal in the reference chassis, time of receiving the optical burst test signal, and a transmission timeslot number carried in the optical burst test signal, a time-phase difference between the receive port corresponding to each OR and the output port corresponding to the FTL that transmits the optical burst test signal in the reference chassis, and adjust, according to the time-phase difference, a clock phase referenced for receiving electrical burst data on the receive port corresponding to the OR and a clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

10. The line card chassis according to claim 9 , wherein the receive port corresponding to the OR adjusts, according to the time-phase difference and an optical path difference between the output port corresponding to the OR and the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR, the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

11. The line card chassis according to claim 10 , wherein: the output port corresponding to each FTL is further configured to transmit an optical burst loopback signal to a receive port corresponding to an OR located in the same line card chassis and corresponding to the FTL, wherein the optical burst loopback signal carries a transmission timeslot number, and the receive port corresponding to the OR is further configured to acquire, according to time of receiving the optical burst loopback signal and the timeslot number carried in the optical burst loopback signal, an optical path difference between the receive port corresponding to the OR and the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

12. The line card chassis according to claim 9 , wherein the receive port corresponding to the OR is further configured to count, according to a preset phase detection period, a local clock between two or more than two consecutively received optical burst test signals, and record a count result, and adjust, according to two consecutive count results, the clock phase referenced for receiving electrical burst data on the receive port corresponding to the OR and the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL located in the same line card chassis and corresponding to the OR.

13. An optical network switching node in a multi-chassis cluster, comprising the line card chassis and all-optical switching element according to claim 9 , wherein: the all-optical switching element comprises multiple input ends and multiple output ends; each output port of each receive-end electrical switching element is connected, by using an FTL connected to the output port, to an input end of the all-optical switching element, and each receive port of each transmit-end electrical switching element is connected, by using an OR connected to the receive port, to an output port of the all-optical switching element; each receive-end electrical switching element is configured to receive multiple data units through multiple receive ports of the receive-end electrical switching element, perform stage-1 electrical switching for the received multiple data units, and after electrical/optical conversion is performed by FTLs connected to multiple output ports of the receive-end electrical switching element, output the multiple data units to the all-optical switching element; the all-optical switching element is configured to perform all-optical space division switching for the multiple data units output by the receive-end electrical switching element, and output the multiple data units to the transmit-end electrical switching element; and the transmit-end electrical switching element is configured to perform optical/electrical conversion, by using ORs connected to multiple receive ports of the transmit-end electrical switching element, for the multiple data units output by the all-optical switching element, and then perform stage-2 electrical switching for the multiple data units after the optical/electrical conversion, and output the multiple data units through multiple output ports of the transmit-end electrical switching element.

14. The optical network switching node in the multi-chassis cluster according to claim 13 , wherein: the all-optical switching element is an arrayed waveguide grating router (AWGR); each FTL is connected to an input end of the AWGR; each OR is connected to an output end of the AWGR; an FTL and a corresponding OR are located in a same line card chassis, and are respectively connected to an input end and an output end of the same AWGR; output ports with same numbers, in all receive-end electrical switching elements, are respectively connected, by using FTLs connected to the output ports, to different input ends of the same AWGR; and input ports with same numbers, in all transmit-end electrical switching elements, are respectively connected, by using ORs connected to the input ports, to different output ends of the same AWGR.

15. The optical network switching node in the multi-chassis cluster according to claim 14 , wherein: each FTL is configured to receive an electrical time division burst data unit on an output port of the receive-end electrical switching element connected to the FTL, convert the electrical time division burst data unit into a time division optical burst signal, and transmit the time division optical burst signal to the AWGR; each AWGR is configured to switch time division optical burst signals from different FTLs in a same timeslot to different output ends to transmit the time division optical burst signals to the OR; and each OR is configured to receive a time division optical burst signal transmitted by the AWGR on one output end, and convert the time division optical burst signal into an electrical time division burst data unit, and then send the electrical time division burst data unit to an input port of the transmit-end electrical switching element connected to the OR.

16. The optical network switching node in the multi-chassis cluster according to claim 14 , wherein each AWGR simultaneously receives time division optical burst signals in a same timeslot, and simultaneously transmits the time division optical burst signals switched to different output ends, to the OR connected to each output end.

17. A line card chassis, comprising: a receive-end electrical switching element and a transmit-end electrical switching element, wherein the receive-end electrical switching element comprises multiple receive ports, multiple output ports, and a wavelength-tunable optical transmission laser (FTL) connected to each output port, and the transmit-end electrical switching element comprises multiple receive ports, multiple output ports, and an optical receiver (OR) connected to each receive port, wherein: the output port corresponding to each FTL is configured to transmit an optical burst test signal from the line card chassis to a receive port corresponding to an OR in a line card chassis that is connected to a same all-optical switching element as the line card chassis and selected as a reference chassis, receive a time-phase difference between the output port corresponding to the FTL in the line card chassis and the receive port corresponding to the OR in the reference chassis, from the receive port corresponding to the OR in the reference chassis, and adjust, according to the time-phase difference, a clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL, wherein the optical burst test signal carries a transmission timeslot number, and the time-phase difference is acquired by the receive port corresponding to the OR in the reference chassis according to an optical path difference between the receive port corresponding to the OR in the reference chassis and the output port corresponding to the FTL that transmits the optical burst test signal in the line card chassis, time of receiving the optical burst test signal transmitted by the output port corresponding to the FTL in the line card chassis, and the transmission timeslot number carried in the optical burst test signal; and the receive port corresponding to each OR is configured to receive, when the line card chassis is selected as a reference chassis, an optical burst test signal transmitted by an output port corresponding to an FTL in other line card chassis that are connected to the same all-optical switching element as the reference line card chassis, acquire, according to an optical path difference between the receive port corresponding to each OR and the output port corresponding to the FTL in the other line card chassis, time of receiving the optical burst test signal transmitted by the output port corresponding to the FTL in the other line card chassis, and a transmission timeslot number in the optical burst test signal, a time-phase difference between the receive port corresponding to each OR and the output port corresponding to the FTL in the other line card chassis, and transmit the time-phase difference to the output port corresponding to the FTL in the other line card chassis, so that the output port corresponding to the FTL in the other line card chassis adjusts, according to the time-phase difference, a clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL in the other line card chassis.

18. The line card chassis according to claim 17 , wherein the output port corresponding to the FTL in the line card chassis is further configured to count, according to a preset phase detection period, a local clock between two or more than two consecutively received time-phase differences returned by the receive port corresponding to the OR in the reference chassis, and record a count result, and adjust, according to two consecutive count results, the clock phase referenced for transmitting electrical burst data on the output port corresponding to the FTL.

19. An optical network switching node in a multi-chassis cluster, comprising the line card chassis and all-optical switching element according to claim 17 , wherein: the all-optical switching element comprises multiple input ends and multiple output ends; each output port of each receive-end electrical switching element is connected, by using an FTL connected to the output port, to an input end of the all-optical switching element, and each receive port of each transmit-end electrical switching element is connected, by using an OR connected to the receive port, to an output port of the all-optical switching element; each receive-end electrical switching element is configured to receive multiple data units through multiple receive ports of the receive-end electrical switching element, perform stage-1 electrical switching for the received multiple data units, and after electrical/optical conversion is performed by FTLs connected to multiple output ports of the receive-end electrical switching element, output the multiple data units to the all-optical switching element; the all-optical switching element is configured to perform all-optical space division switching for the multiple data units output by the receive-end electrical switching element, and output the multiple data units to the transmit-end electrical switching element; and the transmit-end electrical switching element is configured to perform optical/electrical conversion, by using ORs connected to multiple receive ports of the transmit-end electrical switching element, for the multiple data units output by the all-optical switching element, and then perform stage-2 electrical switching for the multiple data units after the optical/electrical conversion, and output the multiple data units through multiple output ports of the transmit-end electrical switching element.